1. Field of the Invention
The present disclosure relates to a scroll compressor having a rotation shaft insertion hole and a fabrication method thereof, and more particularly, to a scroll compressor in a form that part of the rotation shaft is inserted into a fixed scroll in a penetrating manner and a fabrication method thereof.
2. Description of the Related Art
Scroll compressor may include a fixed scroll having a fixed wrap and a circulating scroll having a circulating wrap, which is a compressor in the form of inhaling and compressing refrigerant through a continuous volume change of the compression chamber formed between the fixed wrap and the circulating wrap while the circulating scroll performs a circulating movement on the fixed scroll. The scroll compressor continuously performs inhalation, compression and discharge, and thus has excellent characteristics in the aspect of vibration and noise generated during its operational process compared to other types of compressors.
On the other hand, the circulating scroll is typically formed with a disk shaped end plate and the circulating wrap at the side of the end plate. Furthermore, a boss portion is formed at a rear surface on which the circulating wrap is not formed and connected to a rotation shaft for circulating the circulating scroll. Such a shape may form a circulating wrap over a substantially overall area of the end plate, thereby decreasing a diameter of the end plate portion for obtaining the same compression ratio. However, on the contrary, the operating point to which a repulsive force of refrigerant is applied and the operating point to which a reaction force for cancelling out the repulsive force is applied are separated from each other in the vertical direction during compression, thereby causing a problem of increasing vibration or noise while the circulating scroll is tilted during the operational process.
As a method for solving such problems, there has been disclosed a scroll compressor in the form that a position at which the rotation shaft and the circulating scroll are combined with each other is formed on the same surface as the circulating wrap. In such a type of compressor, the operating point of a repulsive force and the operating point of the reaction force are applied at the same position, thereby solving a problem that the circulating scroll is inclined. However, when the rotation shaft is extended up to the circulating wrap in this manner, an end portion of the rotation shaft should pass through the end plate portion, and thus a shaft insertion hole should be formed at the end plate portion of the circulating scroll to the extent corresponding to the diameter of the rotation shaft. Due to this, there has been a problem of deteriorating a strength of the end plate portion. Moreover, as increasing the diameter of the shaft insertion hole formed at the end plate portion, the possibility of leaking compressed refrigerant is increased.
In order to solve the foregoing problem, as disclosed in Korean Patent Application No. 10-2011-0046492, there has been used a scheme in which a pin portion having a small diameter is formed at an end portion of the rotation shaft, and only the pin portion passes through the end plate portion of the circulating scroll, and an eccentric bush is inserted into the pin portion to form an eccentric portion. Through this, the diameter of the shaft insertion hole formed at the circulating scroll can be reduced, but a compression force may be applied to the pin portion having a small diameter, thereby reducing the strength as well as causing deformation due to this. Moreover, a processing deviation between the eccentric bush and pin portion may cause abrasion between the eccentric bush and pin portion when they are used for a long period of time, thereby deteriorating the bearing performance.